WASHINGTON ― As they have done time and again following mass shootings, former Rep. Gabby Giffords (D-Ariz.) and her husband, former astronaut Mark Kelly, on Monday implored Congress to take legislative action in response to Sunday night’s Las Vegas massacre, the deadliest mass shooting in recent U.S. history.

“The nation’s counting on you,” Giffords, who was gravely wounded during a 2011 mass shooting in Tucson, Arizona, said at a news conference on Capitol Hill.

In the years since she was gunned down, Giffords and Kelly have become leading advocates for gun control reforms.

“For years, Gabby and I have been working to get the people in this building to summon the courage to take meaningful action that make our communities safer places to live,” Kelly said, pointing at the U.S. Capitol. “But despite the tragedies in places like Aurora, Newtown and Orlando, despite daily shootings in communities across America, despite senseless, deadly gun-related domestic violence, despite an epidemic of preventable suicides, despite the problem of toddlers shooting toddlers and their parents, the response from Congress has been to do nothing. Absolutely nothing.”

Calling the Las Vegas shooting “domestic terrorism,” Kelly assailed members of Congress and President Donald Trump for offering “thoughts and prayers” while failing to take legislative action that might prevent future mass shootings.

“What we’re hearing today at the Capitol and the White House are thoughts and prayers. Thoughts and prayers are important. We send our thoughts and prayers too. But they are not enough,” Kelly said. “Your thoughts and prayers aren’t going to stop the next shooting. Only action and leadership will do that.”

“We need a president who recognizes that we have a gun violence problem and will work towards solutions,” Kelly said of Trump, who offered his condolences to shooting victims in a short statement from the White House, but made no mention of guns. “Americans need more than our president’s prayers. We need his plans.”

Kelly also responded to criticism that gun control advocates politicize mass shootings.

“If not now, when?” Kelly asked, rejecting pro-gun claims that it’s insensitive to talk about gun control after a mass shooting. “You know, when you are not going to talk about it on a day like this, how many times can we say that over and over again, ‘Now is not the time?’ Well, today is the time.”